Field-control switch.



W. A. ATWOOD.

FIELD CONTROL SWITCH.

AEPLICATION FILED JUNE 28. 1913.

: 1,229,014. PatentedJune 5,1917.

2 SHEETS-SHEET I- witnessijz Inven or Winfield A.Atwood.

His Attorney.

W. A. ATWOOD.

FIELD CONTROL SWITCH.

APPLICATION FILED JUNE 28. 1913.

Patented June 5, 1917.

2 SHEETS-SHEET 2- Fig.4.

Fig.5.

- quence.

UNITED STATES PATENT OFFICE.

WINFIELD A. ATWOOD, 0F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELEC- TRIC COMPANY, A CORPORATION OF NEW YORK.

FIELD-CONTROL SWITCH.

Specification of Letters Patent.

Patented June 5, 1917.

Application filed .Tune 28, 1913. Serial No. 776,282.

To all whom it may concern:

Be it known that I, WINFIELD A. An WOOD, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Field-Control Switches, of which the following is a specification.

My invention relates to electric switches, and more particularly to field switches for dynamo-electric machines.

More specifically my invention relates to solenoid-operated switches which automatically close the field circuit of a dynamo-electric machine through a resistance, just before the main circuit is broken, whereby the energy of the current resulting from the electromotive force produced by the sudden collapse of the field is dissipated and the well known attendant disturbances eliminated.

switching mechanism for the main field cir cuit and for the resistance circuit which will coact automatically and in proper se- A further object of my invention is to provide a mechanism which will be positive in its action, occupying a minimum amount of space and which is in general an improvement upon previous switches of this character.

The novel features which I believe to be characteristic of my invention will be definitely indicated in the claims appended hereto; the features of construction and mode of operation will be best understood by refer ence to the following description taken in connection with the accompanying drawings in which Figure 1 is a front elevation of a swit'chfembodying the novel features of my invention; Fig. 2 shows the application of the switch hand closing member; and Figs.

3: and tare end elevationspartly in section along the line A-A of Fig. 1 showing the main switch in open and closed positions and having one pole of this switch removed for the purpose of clearness.

Referring to the drawings, the switch construction shown comprises the cooperating main contacts 1 and -2, the movable main contacts 2 being of the usual laminated type and adapted to be putunder a spring tension when the switch is closed. In connection with the main contacts are the auxiliary or shunt contacts 3 and 4 arranged to separate after the main contacts have broken engagement. The main contacts 1 and 2 and the corresponding auxiliary contacts 3 and 4: will hereafter be referred to as the main switch or the main field switch. Between the two poles of the main switch, as shown more clearly in Fig. 1, there is located an auxiliary or discharge switch for the dynamo electric machine comprising the movable contact member 5 and a cooperating fixed contact member 6. The movable contact member 5 is arranged to automatically close or open the field discharge resistance circuit in response to movement of the main switch contacts, by a novel coacting mechanism which will be hereinafter more fully described.

When the main switch is closed, the discharge or auxiliary switch is open, as shown in Fig. 3, so that no energy is consumed by the resistance which is thrown into the field circuit when the discharge switch is closed. During the operation of opening the main switch, however, and just before the main contacts separate, the discharge switch is automatically closed, thereby short circuiting the field winding through a resistance in order to efficiently dissipate the energy of the inductive kick so that the main switch opens with no disastrous effects. The inductive kick is understood as the energy of the current resulting from the electromotive force produced by the sudden change of intensity of the field magnetism. The discharge switch remains closed While the main switch is opened as shown in Fig. 4.. Upon closing the main switch, and before the shunt contacts 3 and 4 come into engagement, the discharge switch is automatically opened, to' eliminate the resistance from the field circuit. Throwing a resistance into the field circuit to reduce the excessive arcing due to the inductive kick when the main switch opens, is well known in the art, but by my invention the aforementioned operations may be most efiiciently and economically carried out, the sequence of operation of the switches being entirely automatic.

The type of switch construction shown in Fig. 1, as an embodiment of my invention, has two poles, each comprising the two movable main and auxiliary contacts 2 and 4 respectively, which are suitably mounted upon the frames 7 which are in turn connected by means of the rocker arms 8 to a common shaft 9. This shaft is actuated to move the main and auxiliary contacts of each pole into or out of circuit closing position. Links 10 are pivotally connected, at one end to the rocker arms 8 and at their other end to the switch support, to firmly support the switch frame and to facilitate the movement of the rocker arms 8. Rotatably mounted upon the shaft 9 is a U-shaped member 11 having bifurcated ends. Pivotally connecting each of the bifurcated ends, is another substantially U-shaped member 12 preferably integral, which is in turn mounted between the protective plates 13 upon the shaft 14. Mounted upon the same shaft 14,

I is an actuating lever member 15 which has at its. other end preferably a roller bearing 16 mounted upon a shaft 17. The actuating lever 15 is arranged with a contact surface 18 which. coacts with the contact surface 19 of the U-shaped member 12, to actuate the U-shaped members 11 and 12, the. rocker arms 8, shaft 9, and the links 10, to close the main switch. Whether the main switch is open or closed, shaft 17 of the roller bearing 16 rests upon the bearin supports 20 which is the normal position 0 the actuating lever member 15. A rubber bufi'er shock absorber is held in position. against roller 16 by supports 20. Upon opening the main switch, the contact surface 19 of the U-shaped member 12 comes into engagement with the contact surface 18 of the actuating member 15 and limits the opening movement of the switch.' The engagement of the contact surfaces 18 and 19 to arrest the movement of the main switch in opening, is shown in Fig. 4. The mechanism so fai -described is that put into operation to close the main switch and may be called collectively the circuit closing mechanism of the'main switch.

Pivotally mounted upon a shaft 21, which passes through the U-shaped member 12, are

' toggle links 22 and, pivotally connected with these toggle links, is a cooperating UQshaped toggle member 23 acting with the toggle links 22 to lock the main switch in its closed position. The U-shaped toggle member 23 is mounted between the protective plates 13 upon a shaft 24 which is journaled 1n the protective plates. This U-shaped member has a lug 25 so positioned that an impact upon it will cause the toggle member 23 to move and, in its moving, to lift the toggle member 22. The latching toggle 2223 then collapses permitting the U-shaped member 12 to move toward member 15 thus allowing the spring action of members 2 to open the main switch. The toggle links 22 each have at their ends a finger 26 which rests upon the shaft 24 when the toggle members are in their rigid or closed position and which prevents the toggle members from being moved beyond center.

Cooperating with the toggle member 23 is a tripping mechanism 28 secured to a shaft 27 which is in turn pivotally mounted between theprotective casings 13. This tripping mechanism is comprised of the bifurcated arms 28 and the dogs 29 preferably integral. At one end, the bifurcated arms 28 are connected by a shaft upon which is mounted a rollerbearing 30 and at the other end the arms terminate in shoulders 31 suitably positioned to make contact with the lug 25 when the trip ing mechanism is actuated. The extent 0 travel of the tripping mechanism is limited in its tripping movement by the dogs 29, the ends'of whichter minate in a curved surface adapted to en gage with the shaft 17 as shown in Fig. 4.

This tripping mechanism coacts with the toggle members 22 and 23, and forms what may be called the circuit opening mechanism of the main switch.

The circuit closing and the circuit 0pen v ing mechanisms for operating the main switch contacts have been described and I .will now outline the methods by which these switch to op'en. The tripping mechanism is actuated by the core 32 of the solenoid 33, and the plunger rod 42 transmits the movement of member 32 to the rocker arm 28. Inserted in the movable core 32 are the buffers 43 which make it impossible for the movable and the stationary parts of core 32 to be held together by residual magnetism. I

This solenoid 33 is also inclosed in the casing 34, only the upper sectional portion of which is shown in Figs. "3 andv4, and is energized through a circuit which is controlled at a distant point. When the remote 35 when the main switch is closed. When this control tripping switch is closed, the solenoid 33 is energized and lifts its plunger or core 32, which in turn lifts plunger rod 42 which strikes the roller bearing 30 and rocks .23 about .its pivotal point 24, and which actuates the coiiperating toggle members 23 and 22, thus collapsing the toggle. Under the spring tension of the laminated contact members 2, the main switch opens and assumes the position shown in Fig. 4. After the tripping mechanism has opened the switch, it proceeds in its movement until arrested by the dogs 29 coming into contact with the shaft 17. The extent of opening of the switch is limited by the engagement of the contact surface 19 of the U-shaped member 12 with the contact surface 18 of the lever 15, as shown in Fig. 4.

In closing the main switch, it is only necessary to close the remote control closingcoil circuit which energizes the solenoid and causes it to raise its plunger or core 36 and strike the roller bearing 16. The solenoid 35 is referably inclosed in the casing 34 and is arger and more powerful than the solenoid 33. VVhen the solenoid 35 is thus energized and its plunger rod 36 makes engagement with the roller bearing 16, the

' lever 15 is moved about its pivotal point 14 and in so moving rotates the U-shaped mem-. ber 12 back toward the position it assumes position is reached, the toggle members 22 and 23 reset, to lock the U-shaped member 12 in position. When the U-shaped member 12 is thus actuated, the coiiperating U- shaped member 11 and rocker arm 8, coact to close the main switch. Simultaneous with the actuation of the lever 15, the dogs 29, which rest upon the shaft 17, are moved toward a vertical positionand upon deener'gization of the solenoid 35 the lever 15 drops back so that its shaft 17 again rests upon the supports 20 and the mainswitch assumes theclosed position shown in" Fig. 3. In the description of the drawings up to this point, I have described the operationof electrically closing and opening the main I switch and the mechanism by which this operation is accomplished.

Between the poles of the main switch is a discharge switch comprising the fixed conconnected to the blade member 5 being bifurcated. The other end of the link 40 is movably mounted upon a pin 41 between the bifurcated arms 28 of the tripping mechanism. The mechanism thus described is the actuating mechanism for the discharge switch and coacts with the circuit closing and opening mechanism of the main switch in the following manner: Assume that the contacts of the main switch are closed, as shown in Fig. 3. The bifurcated arms 28 of the tripping means are in their nearest vertical position and in such position the connecting link 40 holds the contact blade member 5 of the discharge switch open. As long as the main switch is closed the disscarge switch remains open.. Upon energization of the solenoid 33 to open the main switch, the plunger or core 32 moves the plunger rod 42 which in turn moves the tripping mechanism so that the shoulders 31 come into engagement with the lug 25 to trip the toggles 22 and 23 and the tripping mechanism in so moving actuates also the link 40 which in turn moves the contact blade 5 toward its coiiperating fixed contact 6. By this arrangement, when the tripping mechanism is actuated, the discharge switch is first closed, and then a short time interval afterward, the movement of the tripping mechanism has progressed far enough for the shoulders 31 to strike the lug 25 and allow the main switch to open, as shown in Fig. 4.

The discharge switch in closing, just before the main switch opens, throws a resistance in series with the field of the dynamoelectric. machine so that when the circuit is finally broken through the main switch the energy of the inductive kick due to the change of intensity of the field magnetism is dissipated in the resistance, thereby greatly reducing the attendant disturbances when the auxiliary contacts 3 and 4 separate. The discharge switch remains closed until the solenoid 35 is energized to close the main switch. When the plunger rod 36 is actuated, it moves the lever 15 and likewise the shaft 17, which forces the dogs 29 and hence the tripping mechanism back to its vertical position. When the toggle members become reset to hold the main switch closed, the tripping mechanism has been moved through a suflicient distance to open the discharge switch as shown in Fig. 3, that is, just before the circuit through the main switch is closed the discharge switch is opened excluding the resistance from the field circuit.

It is sometimes necessary to operate this the same path that it is moved through by the electrical remote control apparatus. Integrally related with this lever 44 at one end is a hook 45, and at the other end a small handle is attached. A projection 47 also integral with the lever 44 is positioned so that it will form a contact surface between the lever 44 and the plunger 36. A small sub-frame carrying rod 46 is attached to is thesolenoid frame 34. To close the main switch. b this method, hook 45 is caught on to r0 46 and the head of projection 47 moved into contact with plunger 36. The 'lever 44 'is now pushed upward and will move plunger 36 upward against roller 16, and the main switch will be closed in the same manner as the foregoing description of the electrical closing operation sets forth. The method of tripping the main switch by hand will best be understood in this case by reference to Figs. 1 and 2, where member 48 represents an extension of the core 32. This member 48 has an enlarged end for the hand contact, as is shown in Fig. 2. By giving member 48 an upward thrust, plunger rod 42 will force member 28 to break the holding toggle 2223 thereby allowing the spring energy stored in member 2 to throw open the main switch. 30 f In the form of switch construction shown and described, the novel mechanism for operating the main and discharge switches is compact, which is an essential feature in switchboard construction, and is entirely automatic in operation, all the functions of the mechanism coacting in response to a remote control switch.

My invention may be embodied in many other forms than that shown and described 4 and I therefore do not wish to be restricted to the specific arrangement and to the details of construction disclosed, but intend to cover by the appended claims all changes and modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is,-

1. In a control device, the combination with a main switch, actuating means for closing said switch, latching means for normally holding said switch closed, a pivotally mounted tripping member, and means for moving said tripping member about its pivot into a position to release said latching means and permit said switch to open, of

an auxiliary switch, and a member pivotally connecting said tripping member and said auxiliary switch for always closing said auxiliary switch as said tripping mem ber moves to tripping position prior to the release of said latching means and for opening said auxiliary switch prior to the closing of said main 'switch. ;2. In a control device, the combination with a main switch, a pivotally mounted actuating member for closing said switch, latching means for normally holdin said switch closed, and a pivotally mounte tripping member, means for moving said member in one direction about its pivot to trip said latching means, said actuating member acting to move said member in the other direction to return said member to initial position, and a connection between said auxiliary switch and said tripping member for closing said auxiliary switch prior to the release of said main switch and for opening said auxiliary switch before the closing of said main switch.

3. The combination with a main switch, an independently movable actuating member for closing said switch, means for moving said actuating member to switch closed position, latching means for holding said switch in closed position, and an independently movable tripping member for releasing said latching means, of an auxiliary switch, and means mechanically connecting said tri ping member and said auxiliary swltch for a ways closing said auxiliary switch before said tripping member reaches into tripping position.

4. The combination of two switches, actuating means for closing one of said switches, latching means holding the switch closed, a tripping member pivotally movable to trip said latching means, and a link pivotally connected between said tripping member and the other of said switches for transmitting the thrust of said tripping member to said other switch and closing it before said tripping member trips said latching means.

5. The combination with a double pole switch, an actuating member movable to close said switch, a latching toggle for holding said switch closed, and a separately mounted tripping member movable into position to collapse said toggle and permit said switch to open, of an auxiliary switch mounted between the poles of said double pole switch, and a connection between said tripping member and said auxiliary switch for closing said auxiliary switch prior to the tripping of said doublepole switch.

6. The combination with a main switch comprising a separately mounted actuating member movable to close said switch, an actuating toggle, latching means for locking said toggle in switch closed position, and an independently movable tripping member for tripping said latching means, of an auxiliary switch, and a member pivoted to said tripping member and to said auxiliary switch for always moving said auxiliary switch to closed position before said tripping member releases said latching means.

7 'InLa device of the character described, in combination with a main switch comprising actuating means for closing said switch, means for moving said means in switch closno ing direction, latching means for holding said switch closed, a tripping member, means for moving said member into position to trip said latching means, and a member carried by said tripping member cooperating with said actuating means to return said tripping member to its initial position as said switch is closed, of an auxiliary switch, and a connection between said auxiliary switch and said tripping member for closing said auxiliary switch before said tripping member trips said latching means.

8. In a device of the character described, the combination with a main switch, an independently movable actuating member for closing said switch, an actuating toggle, latching means for holding said toggle in switch closed position, a pivotally mounted tripping member for collapsing said latching means and allowing said switch to open said I actuating member acting to limit the movement of said switch in circuit opening position, of an auxiliary switch and a pivotal connection between said auxiliary switch and said tripping member for opening said auxiliary switch prior to the closing of said main switch.

9. The combination with a main switch, latching means for holding said switch closed, a pivotally mounted actuating member biasedto initial position and movable about its pivot to close said switch, a pivotally mounted tripping member movable in one direction about its pivot into engagement with said actuating member releasing said latching means during said movement, an auxiliary switch, and a connection between said auxiliary switch and said tripping member for closing said auxiliary switch prior to the release of said latching means and ior holding said tripping member in engagement with said actuating member, the closing movement of said actuating member acting to move said tripping member in the reverse direction, said connection thereby operating to open said auxiliary switch prior to the closing of said main switch.

10. The combination with a main switch, latching means for holding said switch closed, a tripping member, means for moving said tripping member into a position to release said latching means and further into a restrained position, an actuating member for closing said switch and operative to return said tripping member to initial position during its closing movement, an auxiliary switch, and a connection pivoted between said tripping member and said auxiliary switch operative in response to the movements of said tripping member to close said auxiliary switch prior to the release of said latching means and to open said auxiliary switch before said main switch closes.

11. The combination with a main switch, closing means for said switch including an actuating member positioned to limit the opening movement of said switch and movable to close said switch, tripping means for said switch including a tripping member movable into tripping position and on fur ther movement into engagement with said actuating member, an auxiliary switch, and means connecting said switch and said trip ping member for closing said auxiliary switch prior to the opening of said main switch and for holding said tripping member in engagement with said actuating member, said actuating member operating to re turn said tripping member to initial position during its switch closing movement and cause the opening of said auxiliary switch a before said main switch is closed.

12. The combination with two switches, a

tripping member for tripping the first switch and moving farther to a limited position, a connection between said member and the second switch for closing saidsec- 0nd switch in response to the movement of said tripping member prior to the tripping of the first switch and for holding said tripping member in its limited position, an actuating member for closing the first switch and limiting the movement of said tripping member in tripping direction, said tripping member being returned to initial position by the movement of said actuating member ,to close the first switch, said connection operating to open the second switch prior to the closing of the first switch.

18. The combination of two switches operative in a definite sequence, a pivotally mounted actuating member biased in one direction, means for moving said member in the opposite direction to open one switch and subsequently close the other switch, a pivotally mounted tripping member, and means for moving said tripping member in one direction to close the first switch and subsequently open said other switch, said tripping member being movable in the opposite direction in response to said actuating member.

14. The combination with main and auxiliary switches operative in a definite sequence, a tripping member for said main switch operatively connected to said auxiliary switch, means for moving said tripping member in one direction to first close said auxiliary switch then trip said main switch and finally assume a restrained position, an actuating member for closing said main switch and moving said tripping member in the opposite direction to open said auxiliary switch before the main switch is closed.

15. The combination with main and auxiliary switches operative in a definite sequence, closing means for said main switch including an actuating member movable into switch closed position and biased to initial position, tripping means for said main switch including a tripping member moi'able switch closing movement of said actuating to tripping position and then into engagemember, before said main switch is closed. 10 ment with said actuating means, a pivotal In witness whereof, I have hereunto set connection between said tripping member my hand this 25th da of June, 1913.

and said auxiliary switch operative to close WINFIE D A. ATVVOOD. said auxiliary switch before said tripping Witnesses:

member reaches tripping position and to HELEN OREoRn,

open said auxiliary switch in response to the MARGARET A. DELEHANTY.

Copies 0! this patent ma; be obtained for five cents each, by addressing the Commissioner 0: Patents,

Washington, D. 0. 

